<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Copyright (C) 1988-2017 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being "Free Software" and "Free Software Needs
Free Documentation", with the Front-Cover Texts being "A GNU Manual,"
and with the Back-Cover Texts as in (a) below.

(a) The FSF's Back-Cover Text is: "You are free to copy and modify
this GNU Manual.  Buying copies from GNU Press supports the FSF in
developing GNU and promoting software freedom." -->
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
<head>
<title>Debugging with GDB: Python Commands</title>

<meta name="description" content="Debugging with GDB: Python Commands">
<meta name="keywords" content="Debugging with GDB: Python Commands">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Python.html#Python" rel="up" title="Python">
<link href="Python-API.html#Python-API" rel="next" title="Python API">
<link href="Python.html#Python" rel="prev" title="Python">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.indentedblock {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
div.smalllisp {margin-left: 3.2em}
kbd {font-style:oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nocodebreak {white-space:nowrap}
span.nolinebreak {white-space:nowrap}
span.roman {font-family:serif; font-weight:normal}
span.sansserif {font-family:sans-serif; font-weight:normal}
ul.no-bullet {list-style: none}
-->
</style>


</head>

<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
<a name="Python-Commands"></a>
<div class="header">
<p>
Next: <a href="Python-API.html#Python-API" accesskey="n" rel="next">Python API</a>, Up: <a href="Python.html#Python" accesskey="u" rel="up">Python</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Python-Commands-1"></a>
<h4 class="subsection">23.2.1 Python Commands</h4>
<a name="index-python-commands"></a>
<a name="index-commands-to-access-python"></a>

<p><small>GDB</small> provides two commands for accessing the Python interpreter,
and one related setting:
</p>
<dl compact="compact">
<dd><a name="index-python_002dinteractive"></a>
<a name="index-pi"></a>
</dd>
<dt><code>python-interactive <span class="roman">[</span><var>command</var><span class="roman">]</span></code></dt>
<dt><code>pi <span class="roman">[</span><var>command</var><span class="roman">]</span></code></dt>
<dd><p>Without an argument, the <code>python-interactive</code> command can be used
to start an interactive Python prompt.  To return to <small>GDB</small>,
type the <code>EOF</code> character (e.g., <kbd>Ctrl-D</kbd> on an empty prompt).
</p>
<p>Alternatively, a single-line Python command can be given as an
argument and evaluated.  If the command is an expression, the result
will be printed; otherwise, nothing will be printed.  For example:
</p>
<div class="smallexample">
<pre class="smallexample">(gdb) python-interactive 2 + 3
5
</pre></div>

<a name="index-python-1"></a>
<a name="index-py"></a>
</dd>
<dt><code>python <span class="roman">[</span><var>command</var><span class="roman">]</span></code></dt>
<dt><code>py <span class="roman">[</span><var>command</var><span class="roman">]</span></code></dt>
<dd><p>The <code>python</code> command can be used to evaluate Python code.
</p>
<p>If given an argument, the <code>python</code> command will evaluate the
argument as a Python command.  For example:
</p>
<div class="smallexample">
<pre class="smallexample">(gdb) python print 23
23
</pre></div>

<p>If you do not provide an argument to <code>python</code>, it will act as a
multi-line command, like <code>define</code>.  In this case, the Python
script is made up of subsequent command lines, given after the
<code>python</code> command.  This command list is terminated using a line
containing <code>end</code>.  For example:
</p>
<div class="smallexample">
<pre class="smallexample">(gdb) python
Type python script
End with a line saying just &quot;end&quot;.
&gt;print 23
&gt;end
23
</pre></div>

<a name="index-set-python-print_002dstack"></a>
</dd>
<dt><code>set python print-stack</code></dt>
<dd><p>By default, <small>GDB</small> will print only the message component of a
Python exception when an error occurs in a Python script.  This can be
controlled using <code>set python print-stack</code>: if <code>full</code>, then
full Python stack printing is enabled; if <code>none</code>, then Python stack
and message printing is disabled; if <code>message</code>, the default, only
the message component of the error is printed.
</p></dd>
</dl>

<p>It is also possible to execute a Python script from the <small>GDB</small>
interpreter:
</p>
<dl compact="compact">
<dt><code>source <samp>script-name</samp></code></dt>
<dd><p>The script name must end with &lsquo;<samp>.py</samp>&rsquo; and <small>GDB</small> must be configured
to recognize the script language based on filename extension using
the <code>script-extension</code> setting.  See <a href="Extending-GDB.html#Extending-GDB">Extending GDB</a>.
</p>
</dd>
<dt><code>python execfile (&quot;script-name&quot;)</code></dt>
<dd><p>This method is based on the <code>execfile</code> Python built-in function,
and thus is always available.
</p></dd>
</dl>

<hr>
<div class="header">
<p>
Next: <a href="Python-API.html#Python-API" accesskey="n" rel="next">Python API</a>, Up: <a href="Python.html#Python" accesskey="u" rel="up">Python</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
</div>



</body>
</html>
